WITH NATURAL TOXINS

DESCRIPTION

Technical field

The present invention relates to the field of detoxification and, more particularly, to methods for detoxification of contaminated water, food, feed and/or a mixture thereof, for example, with several toxins from microorganisms.

Background

The existence of contaminants in food and/or water may involve a risk to human and animal health. Thus, their presence must be kept at levels that are tolerable from a toxicological point of view. In this sense, a large number of countries have implemented specific regulations that establish the maximum permitted levels of certain contaminants in food and feed [Silano et al., Crit. Rev. Food Sci. Nutr., 2017, 57(10), 2162] Sensitive methods for toxin detection and effective decontamination are therefore needed to eliminate or reduce their presence.

Toxins such as mycotoxins, phycotoxins and cyanotoxins are the largest group of natural contaminants (of biological origin, produced by microorganisms) that most frequently appear in water or in the food chain.

Mycotoxins are secondary metabolites produced by filamentous fungi in the phylum Ascomycota, mainly species of the genera Aspergillus, Penicillium, Fusarium, Claviceps and Alternaria, which can colonize plants cultivated for human and animal consumption. They contaminate raw materials, such as cereals, and food or feed, causing millions of losses to the food industry, and are capable of causing disease and death in both humans and other vertebrates (other mammals, poultry and fish). These toxins are thermostable, have chemical stability and are neither affected by long-term storage nor by industrial processing and manufacturing of food and feed. Phycotoxins, also called marine toxins, are toxic chemical compounds produced by several species of phytoplanktonic microorganisms within the phylum Dinoflagellata. These compounds accumulate mainly in mollusks, fish and crustaceans [Rodriguez et al., Sci Rep, 2017, 7, 40880]. In addition, these compounds can be released to water when dinoflagellates are lysed. This process occurs either naturally or as the result of seawater processing, such as that undertaken at desalinization plants or seafood microbiological depuration plants.

Cyanotoxins are produced by some harmful species of cyanobacteria. These compounds have caused intoxications in humans and animals that, in certain cases, have become fatal [Wood, R., Environ Int, 2016, 91 , 276]. In aquatic ecosystems, the appearance of cyanotoxins has increased and currently poses a serious public health risk. Cyanotoxins are naturally released to water in small amounts. Therefore, when harmful cyanobacteria proliferate, cyanotoxin concentration in fresh water can exceed tolerable levels either for water consumption or for fishing, industrial, agricultural and recreational activities.

Current detoxification methods regarding mycotoxins typically use quenching (adsorption, chelating or sequestering) agents based on their ability to form complexes with them, reducing, mycotoxin absorption in the gastrointestinal tract [Keller et al., Toxins, 2015, 7, 3297; Wielogorska et al., World Mycotoxin J., 2016, 9, 419]. These methods have a questionable effectiveness since they do not remove toxins from the contaminated raw materials. Likewise, quenching methods for cyanotoxins are used, based on coagulation, flocculation, sedimentation, chlorination, ultraviolet irradiation or filtration through different filters, especially activated charcoal or aluminum sulphate [Lucena, E., Hig. Sanid. Ambient., 2008, 8, 291-302] There is no known detoxification methods for marine toxins.

Alternatively, wet detoxification methods for certain mycotoxins have also been described. For example, the international patent application W02010/049893 describes a method for detoxification of food contaminated with aflatoxins by atomizing or nebulizing hydrogen peroxide. However, these methods require a drying step after the treatment which can modify the food properties with undesirable results. The toxin adsorption capacity of nanomaterials has also been studied. For example, Magro et al. [Magro et al, Food Chem., 2016, 203, 505] described the removal of citrinin (a mycotoxin) from biological matrices using magnetite nanoparticles (Fe2C>3, y- Fe2C>3). Regarding cyanotoxins, the use of composite magnetic nanoparticles for removing microcystins from aqueous media has been disclosed in CN106466591. Additionally, U.S. Patent No. 6417423 discloses a method for destroying biological agents and toxins wherein the substance to be destroyed is contacted with finely divided metal oxide nanocrystals. Furthermore, the use of functionalized magnetic bentonite particles to remove microcystin from contaminated water is described in CN103566866. Also, Gao et al. [Gao et al., Water Environ Res., 2012, 84, 562] described the removal of microcystin-LR (MC-LR) from water using iron oxide nanoparticles and microparticles. Although these methods are capable of reducing the concentration of toxins, their effectiveness is conditioned by the number of available active adsorption sites per particle. The nanomaterials used generally present very low adsorption surface sites per particle not being appropriate for detoxification of high concentrations of toxins or in solid matrices. In addition, the design of the decontamination agents described in the prior art makes them not selective. Also, their small sizes make them difficult to recover and/or recycle.

Therefore, it is desirable to develop new methods for detoxification of contaminated food, feed, or beverages, so that they are safe for human and animal health, and animal production. Also new methods suitable for detoxification of solid food matrices, able to remove high concentrations of toxins and, at the same time, to allow the recovery or the recycling of the materials used, are needed.

Brief description of the invention

The authors of the present invention have developed a method for detoxification of contaminated substances comprising providing a particulate magnetic composite material, wherein said particulate magnetic composite material comprises a surface and has a mean diameter particle size between 100 nm and 10 mm, and each particle of said particulate magnetic composite material comprises at least two magnetite particles, wherein said magnetite particles are embedded within a matrix of a non- magnetic material, and wherein there is a physical separation between said magnetite particles that is filled with said matrix of a non-magnetic material. This particulate magnetic composite material, which is preferably biocompatible, presents a high absorption surface area per particle, which makes the method of the present invention efficient and suitable for high concentration of toxins and for detoxification of solid materials. In addition, the magnetic properties of the composite material can be selectively controlled depending on the type of contaminated substance to be partially or completely detoxified.

Therefore, a first aspect of the invention is directed to a method for detoxification of contaminated substances comprising the following steps:

i) providing a particulate magnetic composite material, wherein said particulate magnetic composite material comprises a surface and has a mean diameter particle size between 100 nm and 10 mm, and each particle of said particulate magnetic composite material comprises at least two magnetite particles, wherein said magnetite particles are embedded within a matrix of a non-magnetic material, and wherein there is a physical separation between said magnetite particles that is filled with said matrix of a non-magnetic material;

ii) contacting a contaminated substance with the particulate magnetic composite material of step (i);

wherein the contaminated substance comprises toxins;

wherein a partial or complete transference of said toxins from the contaminated substance to the particulate magnetic composite material by sorption of said toxins on the surface of said particulate magnetic composite material is produced and a partially or completely detoxified substance is obtained; and

iii) magnetically separating the particulate magnetic composite material from the resulting partially or completely detoxified substance of step (ii).

In a preferred embodiment, the method for detoxification as defined above further comprises the following steps:

iv) removing partially or completely the toxins from the surface of said particulate magnetic composite material resulting from step (iii) by washing said particulate magnetic composite material;

v) optionally, drying the particulate magnetic composite of step (iv); and vi) re-using the particulate magnetic composite of step (v) in step (i). Contrary to the methods of the prior art, the method of the present invention can partially or completely remove and/or eliminate the polluting, poisonous or toxic elements, such as toxins, from the contaminated substance since the particulate magnetic composite material to which the toxin is sorbed can be removed, extracted or recovered magnetically. This is due to the presence of at least two magnetite particles in each of the particles of said particulate magnetic composite material, which leads to a significant improvement of the magnetic properties of the particulate magnetic composite material of the present invention. Consequently, the method of the present invention is suitable for the recovery and/or extraction of the particulate magnetic composite material from the resulting partially or completely detoxified substance, allowing its subsequent recycling.

In addition, another advantage of the method of the present invention over the prior art is that the particulate magnetic composite material comprising a surface of the present invention presents a high sorption surface area per particle being appropriate for detoxification of high concentrations of polluting, poisonous or toxic elements such as toxins. Also, as opposed to the methods of the prior art, the mean diameter particle size of the particulate magnetic composite material of the present invention improves the contact with the contaminated substance to be detoxified, particularly in the case of solids. In addition, the design of the particulate magnetic composite material of the present invention, particularly the design of its non-magnetic matrix and its optional functionalization, makes the method for detoxification of the present invention selective to certain types of toxins.

In a second aspect, the present invention refers to the use of a particulate magnetic composite material, wherein said particulate magnetic composite material comprises a surface and has a mean diameter particle size between 100 nm and 10 mm, and each particle of said particulate magnetic composite material comprises at least two magnetite particles, wherein said magnetite particles are embedded within a matrix of a non-magnetic material, and wherein there is a physical separation between said magnetite particles that is filled with said matrix of a non-magnetic material, for detoxification of a contaminated substance; and

wherein the contaminated substance comprises toxins. In a third aspect, the present invention refers to a composition comprising a contaminated substance and a particulate magnetic composite material, wherein said particulate magnetic composite material comprises a surface and has a mean diameter particle size between 100 nm and 10 mm, and each particle of said particulate magnetic composite material comprises at least two magnetite particles, wherein said magnetite particles are embedded within a matrix of a non-magnetic material, and wherein there is a physical separation between said magnetite particles that is filled with said matrix of a non-magnetic material; and wherein the contaminated substance comprises toxins.

Figures

Figure 1. Diagrams of the evolution of mycotoxin concentration (ng/ml) with respect to time (min). Experiments were performed using three different composites, composite A (solution A), composite B (solution B), composite C (solution C) and with no composite (control) in contact with mycotoxins: (A) deoxynivalenol (DON), (B) zearalenone (ZEA), (C) fumonisin B1 (FB1 ), (D) ochratoxin A (OTA), ( E) aflatoxin B1 (AFB1 ), (F) aflatoxin B2 (AFB2), (G) aflatoxin G1 (AFG1 ) and (H) aflatoxin G2 (AFG2). Mycotoxin concentration has been measured in three independent experiments and error bars showing the standard deviation of the experiment results are shown.

Figure 2. Diagram of mycotoxin percentage recovery tests after the extraction and washing of the prepared magnetic composite materials: (A) composite A, (B) composite B and (C) composite C. Mycotoxins are: deoxynivalenol (DON), zearalenone (ZEA), fumonisin B1 (FB1 ), aflatoxin B1 (AFB1 ), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1 ) and aflatoxin G2 (AFG2). Toxin recovery percentage (extraction %) has been measured in three independent experiments and error bars showing the standard deviation of the experimental results are shown.

Figure 3. Diagram of the evolution of cyanotoxin concentration (ng/ml) with respect to time (min). Experiments were performed using three different composites, composite A (solution A), composite B (solution B), composite C (solution C), and with no composite (control) in contact with: (A) microcystin-LR (MC-LR), (B) microcystin-RR (MC-RR) and (C) nodularin (NOD). Toxin concentration has been measured in three independent experiments and error bars showing the standard deviation of the experiments results are shown.

Figure 4. Diagram of cyanotoxin percentage recovery tests after washing the magnetic composite material A: Microcystin-LR (MC-LR), microcystin-RR (MC-RR) and nodularin (NOD). Toxin percentage has been measured in three independent experiments and error bars showing the standard deviation of the experiment results are shown.

Figure 5. Diagram of the concentration (ng/ml) of hydrophilic phycotoxins: (A) saxitoxin (STX), (B) neosaxitosin (NEO) and (C) decarbamoylsaxitoxin (dc-STX), in solution with Composite A at 0 min (initial concentration) and after 180 min of the addition of composite A (final concentration) and in the control solution with no composite, respectively. Toxin concentration has been measured in three independent experiments and error bars showing the standard deviation of the experiments results are shown.

Figure 6. Diagram of lipophilic phycotoxin percentage recovery tests after the extraction and washing of the composite A. Azaspiracid-1 (AZA1 ), Azaspiracid-2 (AZA2), Azaspiracid-3 (AZA3), dinophysistoxin-1 (DTX1 ), dinophysistoxin-2 (DTX2), okadaic acid (OA), Pectenotoxin-2 (PTX2) y 20-methyl spirolide G (SPX20G). Toxin percentage has been measured in three independent experiments and error bars showing the standard deviation of the experiment results are shown.

Detailed description of the invention

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs. As used herein, the singular forms“a,”“an,” and“the” include plural reference unless the context clearly dictates otherwise.

As defined above, in a first aspect, the present invention refers to a method for detoxification of contaminated substances comprising the following steps:

i) providing a particulate magnetic composite material, wherein said particulate magnetic composite material comprises a surface and has a mean diameter particle size between 100 nm and 10 mm, and each particle of said particulate magnetic composite material comprises at least two magnetite particles, wherein said magnetite particles are embedded within a matrix of a non- magnetic material, and wherein there is a physical separation between said magnetite particles that is filled with said matrix of a non-magnetic material; ii) contacting a contaminated substance with the particulate magnetic composite material of step (i);

wherein the contaminated substance comprises toxins;

wherein a partial or complete transference of said toxins from the contaminated substance to the particulate magnetic composite material by sorption of said toxins on the surface of said particulate magnetic composite material is produced and a partially or completely detoxified substance is obtained; and iii) magnetically separating the particulate magnetic composite material from the resulting partially or completely detoxified substance of step (ii).

In a preferred embodiment, the method for detoxification as defined above further comprises the following steps:

iv) removing partially or completely the toxins from the surface of said particulate magnetic composite material resulting from step (iii) by washing said particulate magnetic composite material;

v) optionally, drying the particulate magnetic composite of step (iv); and

vi) re-using the particulate magnetic composite of step (v) in step (i)

In the context of the present invention, the term“detoxification” refers to the partial or complete decontamination, removal, elimination or extraction of polluting, poisonous or toxic elements from contaminated substances, for example toxins, particularly mycotoxins, phycotoxins and cyanotoxins, subfamilies and/or derivatives of the same or a combination thereof.

In the context of the present invention, the term“contaminated” refers to a substance that comprises polluting, poisonous or toxic elements. Non-limiting examples of polluting, poisonous or toxic elements are toxins, particularly mycotoxins, phycotoxins or cyanotoxins, subfamilies and/or derivatives of the same or a combination thereof. In a particular embodiment, the contaminated substance comprises toxins; preferably comprises toxins selected from mycotoxins, phycotoxins, cyanotoxins, subfamilies and/or derivatives of the same or a combination thereof. In the context of the present invention, the expression “contaminated substance” includes the plural expression“contaminated substances” unless the context clearly dictates otherwise.

In a preferred embodiment, the contaminated substance of the present invention is for human and/or animal consumption.

In a preferred embodiment, the contaminated substance is contaminated water, food, feed and/or a mixture thereof.

In a preferred embodiment, the contaminated substance of the present invention is contaminated water, preferably contaminated fresh water, salted water or waste water, more preferably contaminated fresh water, even more preferably contaminated drinking-water.

In a preferred embodiment, the contaminated substance of the present invention is contaminated waste-water, preferably contaminated waste-water from water-treatment or desalination plants.

The term“water” refers to fresh water, salted water and waste water.“Fresh water” comprises naturally occurring water on Earth's surface in ice sheets, ice caps, glaciers, icebergs, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams.“Salted water” comprises water from an estuary, sea or ocean.“Waste water” comprises any water that has been negatively impacted by domestic, industrial, commercial or agricultural activities.

Further, the method of detoxification of the present invention may serve to reduce and/or completely or partially eliminate toxins, preferably cyanotoxins and/or phycotoxins in contaminated water from drinking-water treatment plants, seafood treatment plants, wastewater purification plants and seawater desalination plants among others.

In a preferred embodiment, the contaminated substance of the present invention is contaminated food products or food raw materials. The term“food products” refers to any substances, usually of plant or animal origin, consumed to provide nutritional support for a living organism, human and/or animal. The term“food raw materials” refers to feedstock or unprocessed materials used to produce food products for human or feed for animal consumption. An example of a food raw material is stored grain and the corresponding food product is any grain- based food product. Another example of a food raw material is distilled dried grains (DDGs), particularly distilled dried grains (DDGs) from bioethanol plants. Non-limiting examples of contaminated food products or food raw materials suitable for the detoxification method of the present invention include contaminated food products or food raw materials in the form of solids, liquids, slurries, dissolutions and/or dispersions, preferably in the form of solids. Non-limiting examples of contaminated food products or food raw materials in the form of liquids, slurries, dissolutions and/or dispersions are those for human or animal consumption, preferably of plant or vegetable origin.

In a preferred embodiment, the contaminated substance of the present invention is a food matrix or a liquid matrix used for human or animal consumption. In a preferred embodiment, the contaminated substance of the present invention is a liquid matrix for human consumption, preferably a beverage for human consumption. Non-limiting examples of beverages for human consumption are vegetable-based beverages such as juices; infusions such as coffee or tea; alcoholic drinks such as wine, beer and liquor; soft drinks and /or carbonated drinks.

In a preferred embodiment the contaminated food products or food raw materials suitable for the detoxification method of the present invention include contaminated solid food products or food raw materials. Non-limiting examples of solid food products or food raw materials suitable for the detoxification method of the present invention include flours, cereals, tree nuts, dry fruits, spices and oilseeds.

In a preferred embodiment the contaminated food products or food raw materials suitable for the detoxification method of the present invention include contaminated fine and/or ultrafine grains, preferably milled grains, more preferably flours. In a preferred embodiment the contaminated food products or food raw materials suitable for the detoxification method of the present invention include contaminated coarse grains, preferably cereals, tree nuts, coffee, dry fruits, spices and oilseeds, more preferably cereals, coffee, tree nuts, spices and oilseeds.

In the context of the present invention, the expression“fine and/or ultrafine grains” refers to food grains with mean diameter particle sizes between 100 nm and 500 pm, for example certain milled food grains such as flours. In the context of the present invention, the expression “coarse grains” refers to food grains with mean diameter particle sizes between 100 pm and 20 mm, preferably between 100 pm and 10 mm.

In a preferred embodiment, the contaminated substance suitable for the detoxification method of the present invention is contaminated with toxins, preferably with mycotoxins, phycotoxins, cyanotoxins, subfamilies and/or derivatives of the same or a combination thereof.

In the context of the present invention the term“toxins” refers to toxic compounds produced within living cells or organisms and can be classified into mycotoxins, phycotoxins, cyanotoxins, subfamilies and/or derivatives of the same or a combination thereof among others. The term“mycotoxin” refers to toxins produced by filamentous fungi in the phylum Ascomycota. The term“phycotoxin” or“marine toxin” refers to toxins produced by phytoplanktonic organisms comprising dinoflagellates. The term “cyanotoxin” refers to toxins produced by cyanobacteria.

Non-limiting examples of toxins suitable for the detoxification method of the present invention include mycotoxins, phycotoxins, cyanotoxins, subfamilies and/or derivatives of the same or a combination thereof.

Non-limiting examples of mycotoxins, phycotoxins and/or cyanotoxins suitable for the detoxification method of the present invention include: deoxynivalenol (DON), zearalenone (ZEA), fumonisin B1 (FB1 ), ochratoxin A (OTA), aflatoxin B1 (AFB1 ), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1 ), aflatoxin G2 (AFG2), microcystin-LR (MC- LR), microcystin-RR (MC-RR), nodularin (NOD), saxitoxin (STX), neosaxitosin (NEO), decarbamoylsaxitoxin (dc-STX), azaspiracid-1 (AZA1 ), azaspiracid-2 (AZA2), azaspiracid-3 (AZA3), dinophysistoxin-1 (DTX1 ), dinophysistoxin-2 (DTX2), okadaic acid (OA), pectenotoxin-2 (PTX2) or 20-methyl spirolide G (SPX20G), subfamilies and/or derivatives of the same or a combination thereof.

In a preferred embodiment, the contaminated substance suitable for the detoxification method of the present invention is contaminated with mycotoxins subfamilies and/or derivatives of the same. Non-limiting examples of mycotoxins suitable for the detoxification method of the present invention include mycotoxins produced by fungi such as Apergillus, Penicillium, Fusarium, Claviceps and/or Alternaria subfamilies and/or derivatives of the same. Non-limiting examples of mycotoxins suitable for the detoxification method of the present invention include trichothecenes, ZEA, fumonisins, aflatoxins, subfamilies and/or derivatives of the same or a combination thereof.

In a more preferred embodiment, the contaminated substance suitable for the detoxification method of the present invention is contaminated with DON, DON diacetate, DON monoacetate, ZEA, a-ZEA, b-ZEA, FB1 , fumonisin B2, fumonisin B3, OTA, AFB1 , AFB2, AFG1 and AFG2, subfamilies and/or derivatives of the same or a combination thereof; more preferably DON, ZEA, FB1 , OTA, AFB1 , AFB2, AFG1 or AFG2, subfamilies and/or derivatives of the same or a combination thereof.

In a preferred embodiment, the contaminated substance suitable for the detoxification method of the present invention is contaminated with phycotoxins, subfamilies and/or derivatives of the same. Non-limiting examples of phycotoxins suitable for the detoxification method of the present invention include phycotoxins produced by several microorganisms families (including bacteria) such as Azadinium, Gambierdiscus, Procentrum, Dinophysis, and/or Alexandrium, subfamilies and/or derivatives of the same, among others.

In a preferred embodiment, the contaminated substance suitable for the detoxification method of the present invention is contaminated with diarrhetic shellfish poisoning toxins (DSPs) like okadaic acid (OA) and dinophysistoxins (DTXs), pectenotoxins (PTXs), yessotoxins (YTXs), ciguatoxins (CTXs), paralytic shellfish poisoning toxins (PSPs) including subgroups carbamate, decarbamoyl, deoxydecarbamoyl and N- sulfocarbamoyl compounds, brevetoxins (PbTXs), amnesic shellfish poisoning toxins (ASPs) like domoic acid (DA), azaspiracids (AZAs), cyclic imines (Cl), maitotoxin (MTXs), gambierol, palytoxins (PITXs), tetrodotoxins (TTXs), subfamilies and/or derivatives of the same or a combination thereof.

In a preferred embodiment, phycotoxins suitable for the detoxification method of the present invention include hydrophilic phycotoxins, subfamilies and/or derivatives of the same; preferably saxitoxins, subfamilies and/or derivatives or a combination thereof; more preferably saxitoxin (STX), neosaxitosin (NEO) or decarbamoylsaxitoxin (dc- STX), subfamilies and/or derivatives of the same or a combination thereof.

In a preferred embodiment phycotoxins suitable for the detoxification method of the present invention include lipophilic phycotoxins, subfamilies and/or derivatives of the same; preferably azaspiracids (AZAs), dinophysistoxins (DTXs), okadaic acid (OA), pectenotoxins (PTXs), spirolides (SPXs), subfamilies and/or derivatives of the same or a combination thereof; more preferably azaspiracid-1 (AZA1 ), azaspiracid-2 (AZA2), azaspiracid-3 (AZA3), dinophysistoxin-1 (DTX1 ), dinophysistoxin-2 (DTX2), okadaic acid (OA), pectenotoxin-2 (PTX2) or 20-methyl spirolide G (SPX20G), subfamilies and/or derivatives of the same or a combination thereof.

In a preferred embodiment, the contaminated substance suitable for the detoxification method of the present invention is contaminated with cyanotoxins, subfamilies and/or derivatives of the same. Non-limiting examples of cyanotoxins suitable for the detoxification method of the present invention include cyanotoxins produced by cyanobacteria or blue algae, subfamilies and/or derivatives of the same.

In a preferred embodiment, the contaminated substance suitable for the detoxification method of the present invention is contaminated with microcystins (MCs), nodularins (NODs), cylindrospermopsins (CYNs), anatoxin-a (ATX-a) and analogues, saxitotins (STXs), b-N-methylamino-L-alanine (BMAA), aplysiatoxins and lyngbyatoxins subfamilies and/or derivatives of the same.

In a preferred embodiment, the contaminated substance suitable for the detoxification method of the present invention is contaminated with microcystins (MCs), nodularins (NOD), subfamilies and/or derivatives of the same or a combination thereof; particularly microcystin-LR (MC-LR), microcystin-RR (MC-RR) or nodularin (NOD), subfamilies and/or derivatives of the same or a combination thereof. As defined above, the method of the present invention comprises the step of (i) providing a particulate magnetic composite material, wherein said particulate magnetic composite material comprises a surface and has a mean diameter particle size between 100 nm and 10 mm, and each particle of said particulate magnetic composite material comprises at least two magnetite particles, wherein said magnetite particles are embedded within a matrix of a non-magnetic material, and wherein there is a physical separation between said magnetite particles that is filled with said matrix of a non-magnetic material. The expression “composite material” refers to a material made from at least two constituent materials with significantly different physical or chemical properties, that when combined produce a material with different characteristics from the individual components. In the present invention the composite material is a“magnetic composite material” since it presents magnetic properties, preferably superparamagnetic properties. In the present invention, the magnetic composite material is a“particulate magnetic composite material” because it comprises particles of a magnetic composite material.

According to the invention each particle of the particulate magnetic composite material of the present invention comprises at least two magnetite particles, preferably at least 5 magnetite particles, more preferably at least 10 magnetite particles, even more preferably at least 20 magnetite particles; even more preferably at least 100 magnetite particles. According to the present invention, the magnetite particles present in the particles of the particulate magnetic composite material of the present invention are embedded within a matrix of a non-magnetic material, wherein there is a physical separation between said magnetite particles that is filled with a matrix of a non-magnetic material as described herewith.

In a preferred embodiment, the particulate magnetic composite material of the present invention is a “magnetic multicore material” because it comprises particles of a magnetic composite material and each particle comprises at least two magnetite particles. In a preferred embodiment, the particulate magnetic composite material has a mean diameter particle size between 100 nm and 10 mm, preferably between 100 nm and 500 pm; more preferably between 200 nm and 400 pm.

In a preferred embodiment, the particulate magnetic composite material of the present invention has a mean diameter particle size between 100 pm and 10 mm.

In the context of the present invention, the term“mean particle diameter” or“mean diameter particle size” refers to the Particle Size Distribution D50, also known as the “median diameter” or the“medium value” of the particle size distribution and it is the value of the particle diameter at 50% in the cumulative distribution. For example, if D50=5.8 microns, then 50% of the particles in the sample are larger than 5.8 microns, and 50% smaller than 5.8 microns.

The particulate magnetic composite material can be prepared by standard methods known in the state of the art [Burke, N. A. D. et al., Chem. Mater., 2002., 14, 4752; Zhu, M. et al, Nanoscale, 201 1 , 3, 2748; Behrens, S., Nanoscale, 201 1 , 3, 877] As a non- limitative example, the particulate magnetic composite material is prepared by a process comprising the following steps (i) dispersing at least two magnetite particles within an aqueous or an organic solvent or a combination thereof; (ii) adding a non- magnetic material precursor to the resulting dispersion of (i); (iii) embedding at least two magnetite particles within a matrix of a non-magnetic material wherein there is a physical separation between said magnetite particles that is filled with a matrix of the non-magnetic material described herewith. Optionally, the resulting material of either steps (i), (ii) or (iii) can be chemically functionalized; preferably, with ligands; more preferably with organic compounds comprising carboxylic groups. Optionally, each particle of said particulate magnetic composite material can be chemically functionalized. Then, the resulting material can be optionally thermally treated at temperatures below 400°C. The resulting material can be optionally treated under different mechanization processes to generate different morphologies such as pellets. The resulting material can be treated by a further optional step wherein the surface of said particulate magnetic composite material can be chemically functionalized preferably, with ligands; more preferably with organic compounds comprising carboxylic groups. Non-limiting examples of “mechanization processes” suitable for the particulate magnetic composite material of the method of the present invention include fusion, extrusion, abrasion, milling or rolling processes.

Non-limiting examples of said “morphologies” suitable for the particulate magnetic composite material of the method of the present invention include aggregated, pelletized, cylindrical, discoidal, spherical, tabular, ellipsoidal, cubic, acicular, flakey, angular, equant or irregular shapes.

In the context of the present invention, the expression “non-magnetic material precursor” refers to chemical compounds that can react to form a matrix of the non- magnetic materials described above.

Furthermore, the particulate magnetic composite material of the present invention presents magnetic properties, preferably superparamagnetic. The magnetic properties of the particulate magnetic composite material are due to the presence of at least two magnetite particles as a constituent of each particle of the particulate magnetic composite material. In fact, it has been observed that, for example, when the magnetite particles are superparamagnetic, the particulate magnetic composite material is also superparamagnetic. Therefore, by selecting the magnetic properties of the at least two magnetite particles, the magnetic properties of the particulate magnetic composite material can be effectively selected too.

The term “magnetite” refers to one of the oxides of iron with the chemical formula Fe ₃ 0 ₄ . The expression“magnetite particles” refers to Fe3<D ₄ particles. In the context of the present invention, the expression“magnetite particle” includes the plural expression“magnetite particles” unless the context clearly dictates otherwise.

In a preferred embodiment, the at least two magnetite particles of the present invention are superparamagnetic; preferably the at least 10 magnetite particles of the present invention are superparamagnetic.

In a particular embodiment, the particulate magnetic composite material is superparamagnetic. The term“superparamagnetic” refers to a material having a mean magnetic moment which in absence of an external magnetic field is 0/null. In presence of an external magnetic field (different from null) said material has a magnetization with an intensity M. A magnetic composite material particle containing N superparamagnetic magnetite particles shows a magnetic moment N times greater that the intensity of the magnetic moment of one superparamagnetic magnetite particle in presence of the same external magnetic field, being N the number of superparamagnetic magnetite particles present in said magnetic composite material particle and also being N at least 2.

Without being bound to any particular theory, the authors of the present invention have observed that since each particle of the particulate magnetic composite material of the present invention, which includes at least two magnetite particles, presents a magnetic moment N times greater that the intensity of the magnetic moment of one superparamagnetic magnetite particle, the magnetic properties of the particulate magnetic composite material of the present invention are improved. Consequently, the method of the present invention is efficient and suitable for the recovery and/or extraction of the particulate magnetic composite material from the resulting partially or completely detoxified substances allowing its subsequent recycling.

According to the invention, each particle of the particulate magnetic composite material of the present invention comprises at least two magnetite particles; preferably at least 10 magnetite particles.

According to the invention, there is a physical separation between the magnetite particles present in the particles of the particulate magnetic composite material of the present invention.

According to the invention, the magnetite particles present in the particles of the particulate magnetic composite material of the present invention, are embedded within a matrix of a non-magnetic material.

According to the invention, there is a physical separation between the magnetite particles present in the particles of the particulate magnetic composite material of the present invention that is filled with a matrix of a non-magnetic material as defined herein. In a particular embodiment, the magnetite particles present in the particles of the particulate magnetic composite material of the present invention, are physically separated (not in contact) from the magnetite particles present in the same particle of the particulate magnetic composite material of the present invention.

In a particular embodiment, the magnetite particles present in the particles of the particulate magnetic composite material of the present invention are chemically functionalized. In a preferred embodiment, the chemical functionalization suitable for the magnetite particles present in the particles of the particulate magnetic composite material of the present invention includes compounds comprising carboxylic groups, preferably alginate.

In a particular embodiment, the magnetite particles present in the particles of the particulate magnetic composite material of the present invention, have a non-magnetic material surrounding the surface of each of said magnetite particles, particularly a continuous or discontinuous film, more particularly a continuous film.

In a preferred embodiment, the mean diameter particle size of the magnetite particles present in the particles of the particulate magnetic composite material of the present invention is below 30 nm, preferably between 1 nm and 25 nm, more preferably between 5 nm and 20 nm; even more preferably around 10 nm.

In a preferred embodiment, the particulate magnetic composite material of the present invention is superparamagnetic and it comprises superparamagnetic magnetite particles having a mean diameter particle size below 30 nm.

In a particular embodiment, the particulate magnetic composite material of the present invention comprises between 10 and 90 wt% of the magnetite particles present in the particles of the particulate magnetic composite material of the present invention, with respect to the total weight of the composite material, preferably between 10 and 50 wt%, more preferably between 20 and 40 wt%.

In the context of the present invention, the expression“non-magnetic material” refers to a porous or non-porous material that does not present magnetic properties. Said material can be in the form of a matrix embedding the magnetite particles present in the particles of the particulate magnetic composite material of the present invention, and filling the physical separation between said magnetite particles. Optionally, said non-magnetic material can be in the form of a continuous or discontinuous, mono or multilayer film around the surface of said magnetite particles.

It has been observed that the presence of said non-magnetic material surrounding the surface of each of the magnetite particles present in the particles of the particulate magnetic composite material of the present invention, avoids the aggregation of said magnetite particles leading to a better magnetite particle distribution and/or dispersion. Consequently, the magnetic properties of the magnetite particles are preserved within the particulate magnetic composite material.

Non-limiting examples of said“non-magnetic material” suitable for the method of the present invention includes biocompatible organic and inorganic materials such as metals, cobalt alloys, titanium alloys, aluminum oxide, zirconia, calcium phosphates, silicones, poly (ethylene), poly (vinyl chloride), polyurethanes, polylactides, collagen, gelatin, elastin, silk, polysaccharide and derivatives of the same, chitosan, glucoman, polvinil pirrolidone, polyacrilic acid, polyethylenimine, carbon- and silica-based materials and clays, or combinations thereof.

In a preferred embodiment, the“non-magnetic material” suitable for the method of the present invention is in the form of a matrix embedding the magnetite particles present in the particles of the particulate magnetic composite material of the present invention and filling the physical separation between said magnetite particles. Preferably, the “non-magnetic material” suitable for the method of the present invention is a carbon- based material or a metal oxide matrix, more preferably is a carbon matrix or a silicon- based material matrix, even more preferably is a carbon matrix or a silica (Si0 ₂ ) matrix.

In another preferred embodiment, the“non-magnetic material” suitable for the method of the present invention is a carbon based material matrix, particularly a carbon matrix.

In another preferred embodiment, the“non-magnetic material” suitable for the method of the present invention is a silica matrix, particularly a mesoporous silica matrix. In the context of the present invention, the expression“silica” refers to silicon dioxide.

In another preferred embodiment, the“non-magnetic material” suitable for the method of the present invention is chemically functionalized; preferably the “non-magnetic material” in the form of a matrix suitable for the method of the present invention is chemically functionalized, more preferably the“non-magnetic material” suitable for the method of the present invention in the form of a porous matrix is chemically functionalized.

In a preferred embodiment, the surface of the particulate magnetic composite material of the present invention is chemically functionalized.

Without being bound to any theory in particular, the authors of the present invention have observed that the functionalization of the“non-magnetic material” suitable for the method of the present invention or the functionalization of the surface of the particulate magnetic composite material suitable for the method of the present invention, further increases the final surface area of each particle of the particulate magnetic composite material of the present invention and further increases the number of available active sorption sites per particle, improving the interaction with the polluting, poisonous or toxic elements, such as toxins, involved in the method for detoxification of contaminated substances of the present invention.

Additionally, the chemical functionalization of the“non-magnetic material” suitable for the method of the present invention or of the surface of the particulate magnetic composite material of the present invention can be specifically selected according to the contaminated substance to be partially or completely detoxified in the method of the present invention to increase the selectivity of the particulate magnetic composite material.

In a particular embodiment, the surface of the particulate magnetic material is chemically functionalized; wherein said chemical functionalization comprises ligands; wherein said ligands are able to bond toxins; preferably to selectively bond toxins; more preferably to selectively bond toxins selected from mycotoxins, phycotoxins, cyanotoxins, subfamilies and/or derivatives of the same or a combination thereof; more preferably toxins selected from mycotoxins and/or derivatives of the same. In another particular embodiment, the surface of the particulate magnetic material is chemically functionalized; wherein said chemical functionalization comprises ligands; wherein said ligands are able to trap toxins; preferably to selectively trap toxins; more preferably toxins selected from mycotoxins, phycotoxins, cyanotoxins, subfamilies and/or derivatives of the same or a combination thereof; more preferably toxins selected from mycotoxins and/or derivatives of the same.

In a more particular embodiment, the surface of the particulate magnetic material is porous and chemically functionalized; wherein said chemical functionalization comprises ligands; wherein said ligands are able to bond or trap toxins; preferably to selectively bond or trap toxins; even more preferably toxins selected from mycotoxins, phycotoxins, cyanotoxins, subfamilies and/or derivatives of the same or a combination thereof; more preferably toxins selected from mycotoxins and/or derivatives of the same.

In the context of the present invention the term“bond” refers to a chemical bond; preferably an ionic or covalent bond; more preferably a covalent bond. In the context of the present invention the term“trap” refers to a chemical or physical interaction; preferably a chemical interaction; more preferably an ionic or covalent bond; more preferably a covalent bond.

The term“selectively” in relation with the bonding or trapping of toxins refers to a specific interaction with said toxins. Non-limiting examples of the chemical functionalization of the“non-magnetic material” suitable for the method of the present invention or of the surface of the particulate magnetic composite material of the present invention comprises ligands that are compounds comprising hydrophilic or hydrophobic groups, lipophilic or lipophobic groups, particularly amines, carboxylic groups, silanol groups, thiol groups and/or hydroxyl groups.

In a preferred embodiment, the chemical functionalization suitable for the method of the present invention comprises ligands; preferably organic compounds; more preferably organic compounds comprising amine groups or carboxylic groups, preferably ethylenediamine or alginate. In a preferred embodiment, the chemical functionalization suitable for the method of the present invention includes compounds comprising amine groups, preferably ethylenediamine.

In a preferred embodiment, the chemical functionalization suitable for the method of the present invention includes compounds comprising carboxylic groups, preferably alginate. Furthermore, the method of the present invention as defined above further comprises the step (ii) of contacting the contaminated substances defined above with the particulate magnetic composite material of step (i) wherein the contaminated substance comprises toxins;

wherein a partial or complete transference of said toxins from the contaminated substance to the particulate magnetic composite material by sorption of said toxins on the surface of said particulate magnetic composite material is produced and a partially or completely detoxified substance is obtained.

In the contexts of the present invention, the expression“sorption of said toxins on the surface of said particulate magnetic composite material” refers to either a sorption of the toxins on the naked surface or on the functionalized surface of the particulate magnetic composite material of the present invention.

The step (ii) of the method of the present invention refers to a physical intimate contact between the contaminated substance with the particulate magnetic composite material of the present invention and it can take place in a solution or in solid state; preferably in a solution; more preferably in an aqueous solution. It optionally involves an agitation or stirring processes such as the use of a vortex mixer, ultrasonic agitation or similar techniques to ensure that the particles of the particulate magnetic composite material achieve a physical intimate contact with the contaminated substance. This contact allows the sorption of the polluting, poisonous or toxic elements, particularly toxins, within the contaminated substances to the surface of the particulate magnetic composite material in a physical or chemical process known as“sorption”.

In the context of the present invention, the term“sorption” refers to the process by which a polluting, poisonous or toxic element, for example a toxin becomes absorbed, adsorbed and/or bonded to a surface; wherein said surface can be a“naked” or a functionalized surface; preferably a functionalized surface with ligands. Said sorption may happend through an ion exchange process, a chemical or physical bonding process or through a combination of processes thereof; preferably through a chemical bonding process.

The term“sorbed” refers to a polluting, poisonous or toxic element or elements, for example a toxin or toxins, absorbed, adsorbed and/or bondedto a surface, it also refers to the specific interactions or bonds created between ligands and the polluting, poisonous or toxic element or elements .

In a particular embodiment, the step (ii) of the method of detoxificacion of the present invention further refers to the transference of polluting, poisonous or toxic elements partially or completely from the contaminated substance to the particulate magnetic composite material of the present invention by sorption of said polluting, poisonous or toxic elements on the surface of said particulate magnetic composite material; said transference may be partial or complete; preferably partial.

In a particular embodiment, said transference is complete.

In a particular embodiment, the step (ii) of the method of detoxificacion of the present invention further refers to a reduction of the polluting, poisonous or toxic elements in the contaminated substance; preferably to a reduction of the toxins comprised in the contaminated substance.

In a more particular embodiment, when there is a partial transference, the reduction of polluting, poisonous or toxic elements in the contaminated substance is at least in a 10 % of the initial amount; preferably at least a 20%; more preferably at least a 50%; even more preferably at least a 60%.

In a more particular embodiment, when there is a partial transference, the reduction of the toxins comprised in the contaminated substance is at least in a 10 % of the initial amount; preferably at least a 20%; more preferably at least a 50%; even more preferably at least a 60%. In a particular embodiment, the step (ii) of the method of detoxificacion of the present invention further refers to polluting, poisonous or toxic elements being sorbed on the surface of the particulate magnetic composite material, preferably in the external surface of each of the particles of the particulate magnetic composite material; more preferably in the functionalized surface.

In a particular embodiment said polluting, poisonous or toxic elements are toxins; preferably mycotoxins, phycotoxins or cyanotoxins, subfamilies and/or derivatives of the same or a combination thereof.

Without being bound to any theory in particular, the authors of the present invention have observed that the mean diameter particle size of the particulate magnetic composite material of the present invention, leads to a high surface area and high sorption surface area or capacity per particle which makes the method of the present invention able to process high volumes and/or highly contaminated substances. The expression“high volumes” refers to the quantity of liquids, products or materials usually handled by factories, normally in tons; preferably liquids; more preferably aqueous solutions. The expression “highly contaminated substances” refers to substances (liquid or solid substances) with contamination levels above the law regulations.

The term“surface area per particle” refers to the total area that the surface of an object occupies, in the present case, a particle. Therefore, the term“sorption surface area” refers to the total area at the surface of each particle of the particulate magnetic composite material of the present invention that is available for the polluting, poisonous or toxic elements, for example toxins, to become absorbed, adsorbed and/or bonded through an ion exchange process or through a combination of processes thereof. The term “surface area per mass” refers to the surface area or a certain mass of the particulate magnetic composite material of the present invention and/or to the specific surface area (SSA) as known in the art (for example with units of m ² /g). The values for specific surface area may be obtained by methods of measurement known in the art, for example adsorption based methods such as those using the BET isotherm for example the Brunauer-Emmett-Teller (N ₂ -BET) adsorption method, or may be calculated theoretically from the“mean particle diameter” or“mean diameter particle size” of the particles of the particulate magnetic composite material of the present invention which may be calculated from the particle size distribution obtained from methods known in the art such as microscopic methods among others.

In a preferred embodiment, the particulate magnetic composite material of the present invention has a surface area per particle between 31 pm ² and 1260 mm ² ; preferably between 31 pm ² and 786000 pm ² ; more preferably between 126 pm ² and 503000 pm ² .

In a preferred embodiment, the particulate magnetic composite material of the present invention has a sorption surface area per particle between 31 pm ² and 1260 mm ² ; preferably between 31 pm ² and 786000 pm ² ; more preferably between 126 pm ² and 503000 pm ² .

In a preferred embodiment, the particulate magnetic composite material of the present invention has a surface area per mass between 10 and 500 m ² /g, preferably between 20 and 300 m ² /g, more preferably between 30 and 200 m ² /g.

In a preferred embodiment, the particulate magnetic composite material of the present invention has a sorption surface area per mass between 10 and 500 m ² /g, preferably between 20 and 300 m ² /g, more preferably between 30 and 200 m ² /g.

Furthermore, without being bound to any particular theory, it has been observed that when the contaminated substance or substances are in solid state, the contact between the contaminated substance and the particulate magnetic composite material in step (ii) of the method of the present invention is improved. In particular, when the contaminated substance or substances are food products or food raw materials, particularly fine and/or ultrafine grains or coarse grains, if the mean diameter particle size of the grains is in the same range to those of the particulate magnetic composite material particles, the contact or interaction between both materials during step (ii) of the present invention is optimized and more effective.

In a preferred embodiment, in step (ii) of the method of the present invention, the contaminated substances are in solid state as fine and/or ultrafine grains and the particulate magnetic composite material of the present invention has a mean diameter particle size of between 100 nm and 500 pm. In another preferred embodiment, the contaminated substances are in solid state as fine and/or ultrafine grains and the particulate magnetic composite material has a mean diameter particle size of between 100 nm and 500 pm, even more preferably between 200 nm and 1 pm and it comprises at least two magnetite particles having a mean diameter particle size below 30 nm, more preferably between 1 nm and 25 nm, even more preferably between 5 nm and 20 nm. For these ranges of mean diameter particle sizes, the particulate magnetic composite material and the magnetite particles are preferably superparamagnetic.

In a preferred embodiment, in step (ii) of the method of the present invention, the contaminated substances are in solid state as coarse grains and the particulate magnetic composite material of the present invention has a mean diameter particle size of between 100 pm and 10 mm.

In a particular embodiment, the method for detoxification of the present invention further comprises the step of (iii) magnetically separating the particulate magnetic composite material of the present invention from the resulting partially or completely detoxified substances of step (ii).

In a particular embodiment, the magnetic separation of step (iii) of the method for detoxification of the present invention further comprises that the magnetic driving and separation of the particles of the magnetic composite material is achieved using a permanent magnet.

The magnetic properties of the particulate magnetic composite material allow its magnetic separation in step (iii) of the method of the present invention and thus, removing and/or eliminating partially or completely the polluting, poisonous or toxic elements, such as toxins, described above from the contaminated substances. Additionally, said particulate magnetic composite material can be recycled and reused after a cleaning procedure resulting in economic advantages of the method of the present invention over the prior art. Furthermore, said particulate magnetic composite material is also able to be used in available industrial magnetic separation processes. Indeed, in order to be able to reuse the particulate magnetic composite material for the method of detoxification of the present invention, the toxins sorbed on the surface of the particulate magnetic composite material of step (iii) can be partially or completely removed for example by washing or by a magnetic hyperthermia treatment, preferably by washing.

In a particular embodiment, the method for detoxification of the present invention optionally comprises a step (iv) of removing partially or completely the polluting, poisonous or toxic elements from the surface of the particulate magnetic composite material resulting from step (iii); preferably toxins; more preferably toxins selected from mycotoxins, phycotoxins, cyanotoxins, subfamilies and/or derivatives of the same or a combination thereof.

In a preferred embodiment, in step (iv) of the method of the present invention, the polluting, poisonous or toxic elements, preferably toxins, can be partially or completely removed from the surface of the particulate magnetic composite material resulting from step (iii) by magnetic hyperthermia; more preferably toxins selected from mycotoxins, phycotoxins, cyanotoxins, subfamilies and/or derivatives of the same or a combination thereof.

In a preferred embodiment, the method for detoxification of the present invention optionally comprises the following further steps:

iv) removing partially or completely the toxinsfrom the surface of the particulate magnetic composite material resulting from step (iii) by magnetic hyperthermia; and

v) re-using the particulate magnetic composite of step (v) in step (i).

In a preferred embodiment, in step (iv) of the method of the present invention, the toxins can be partially or completely removed from the surface of the particulate magnetic composite material resulting from step (iii) by washing said particulate magnetic composite material, preferably with a an aqueous, an organic solution or a combination thereof; more preferably by water.

The expression “magnetic hyperthermia” refers to the increase of temperature provoked in magnetic particles, particularly in the particulate magnetic composite material particles of the present invention by the application of an alternating magnetic field that heats up the surrounding medium. This treatment involves the partial or complete removal or elimination of the substances sorbed in the surface of the particulate magnetic composite material, particularly toxins, more particularly mycotoxins, cyanotoxins or phycotoxins subfamilies and/or derivatives of the same or a combination thereof. The term “washing” refers to the immersion of the particulate magnetic composite material in a solution, particularly organic solutions, aqueous solutions or mixtures thereof, such as water, acetonitrile, methanol, water and mixtures thereof, more particularly acetonitrile or methanol. Optionally, it involves acidification or basification of the solution by adding either an acid or a basic compound. It optionally involves agitation or stirring processes such as the use of a vortex mixer, ultrasonic agitation or similar techniques. It also involves the partial or complete removal, extraction or elimination of the polluting, poisonous or toxic elements, particularly toxins, sorbed in the surface of the particulate magnetic composite material of the present invention. In another particular embodiment, the present invention refers to a particulate magnetic composite material that has a mean diameter particle size between 100 nm and 10 mm, and each particle of said particulate magnetic composite material comprises at least two magnetite particles, wherein said magnetite particles are embedded within a matrix of a non-magnetic material, and wherein there is a physical separation between said magnetite particles that is filled with said matrix of a non-magnetic material.

In another particular embodiment, the present invention refers to a particulate magnetic composite material that has been obtained by a process comprising the following steps:

i) dispersing at least two magnetite particles within an aqueous or an organic solvent or a combination thereof;

ii) adding a non-magnetic material precursor to the resulting dispersion of (i); iii) embedding said at least two magnetite particles within a matrix of a non- magnetic material wherein there is a physical separation between said magnetite particles that is filled with a matrix of the non-magnetic material described herewith.

In a particular embodiment, the present invention refers to a particulate magnetic composite material that has been obtained by a process comprising a further optional step wherein the resulting material of either steps (i), (ii) or (iii) can be chemically functionalized; preferably the resulting material of step (iii).

In a particular embodiment, the present invention refers to a particulate magnetic composite material that has been obtained by a process comprising a further optional step wherein the surface of said particulate magnetic composite material is chemically functionalized.

In a particular embodiment, the present invention refers to a particulate magnetic composite material that has been obtained by a process comprising a further optional step as follows:

(iv) the resulting material of (iii) is thermally treated at temperatures below 400°C.

In a more particular embodiment, the present invention refers to a particulate magnetic composite material that has been obtained by a process comprising a further optional step as follows:

(v) the resulting material of (iv) suffers a mechanization process.

In a particular embodiment, the present invention refers to a particulate magnetic composite material that has been obtained by a process comprising a further step as follows: the resulting material comprises a particulate magnetic composite material wherein said particulate magnetic composite material comprises a surface and has a mean diameter particle size between 100 nm and 10 mm, and each particle of said particulate magnetic composite material comprises at least two magnetite particles, wherein said magnetite particles are embedded within a matrix of a non-magnetic material, and wherein there is a physical separation between said magnetite particles that is filled with said matrix of a non-magnetic material.

In another aspect, the present invention refers to the use of a particulate magnetic composite material, wherein said particulate magnetic composite material comprises a surface and has a mean diameter particle size between 100 nm and 10 mm, and each particle of said particulate magnetic composite material comprises at least two magnetite particles, wherein said magnetite particles are embedded within a matrix of a non-magnetic material, and wherein there is a physical separation between said magnetite particles that is filled with said matrix of a non-magnetic material, for detoxification of a contaminated substance; wherein the contaminated substance comprises toxins.

In another aspect, the present invention refers to a composition comprising a contaminated substance and a particulate magnetic composite material, wherein said particulate magnetic composite material comprises a surface and has a mean diameter particle size between 100 nm and 10 mm, and each particle of said particulate magnetic composite material comprises at least two magnetite particles, wherein said magnetite particles are embedded within a matrix of a non-magnetic material, and wherein there is a physical separation between said magnetite particles that is filled with said matrix of a non-magnetic material; and wherein the contaminated substance comprises toxins.

The particulate magnetic composite material used for detoxification of a contaminated substance presents all advantages and characteristics as defined above for the method of detoxification of the present invention. The particulate magnetic composite material of the composition comprising a contaminated substance and a particulate magnetic composite material, presents all advantages and characteristics as defined above for the method of detoxification of the present invention.

Industrial applicability

The method for detoxification of the present invention is useful in a wide variety of applications where the removal of toxins from contaminated substances would be desirable. In one possible application, the method of detoxification of the present invention may serve to reduce and/or completely or partially eliminate toxins in food products or food raw materials for example when they are in the form of liquids, slurries, dissolutions and/or dispersions preferably of plant or vegetable origin or in the form of solid state as grains such as flour or feed grains, distillery subproducts and/or analogous products.

Further, the method of detoxification of the present invention may serve to reduce and/or completely or partially eliminate toxins, preferably mycotoxins, cyanotoxins and/or phycotoxins, in water from drinking-water, water treatment plants, seafood treatment plants, wastewater purification plants and seawater desalination plants among others. The method for detoxification of the present invention is simple, suitable for scale-up production and has wide application prospect on analytical chemistry and environment analysis.

EXAMPLES

Example 1 :

Detoxification tests of mycotoxins

Three particulate magnetic composite materials, named composite A, composite B and composite C, were tested for their detoxification capabilities in the removal of mycotoxins. Appropriate controls were also evaluated in these studies.

Composite A is a particulate magnetic composite material, wherein each particle of said composite A comprises several magnetite particles embedded within a carbon matrix (multi-Fe ₃ 0 ₄ @C particles) wherein said magnetite particles are not in contact with each other and the physical separation between them is filled with said carbon matrix.

Composite B is a particulate magnetic composite material, wherein each particle of said composite B comprises several magnetite particles embedded within a mesoporous silica matrix (multi-Fe304@SiC>2 particles). Said magnetite particles are not in contact with each other and the physical separation between them is filled with said mesoporous silica matrix. Also, said mesoporous silica matrix is functionalized with ethylenediamine groups. Composite C is a particulate magnetic composite material, wherein each particle of said composite C comprises several magnetite particles embedded within a carbon matrix. Said magnetite particles are not in contact with each other and the physical separation between them is filled with said carbon matrix. Also, each of said magnetite particles is functionalized with alginate (multi-Fe ₃ 0 ₄ @Alg@C particles). The mycotoxins selected for the test were deoxynivalenol (DON), zearalenone (ZEA), fumonisin B1 (FB1 ), ochratoxin A (OTA), aflatoxin B1 (AFB1 ), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1 ) and aflatoxin G2 (AFG2). These mycotoxins were obtained from Sigma-Aldrich (Madrid, Spain).

Mass spectrometry (MS) was the analytical technique used to study the mycotoxin concentration in the aqueous solutions. A Nd-Fe-B magnet was used for the magnetic driving and separation of the particles.

Aqueous solutions were prepared as a mixture of the selected mycotoxins with the following concentrations: 12.5 ng/ml of DON, 50 ng/ml of ZEA, 50 ng/ml of FB1 , 50 ng/ml of OTA, 1.75 ng/ml of AFB1 , 1.75 ng/ml of AFB2, 1.75 ng/ml of AFG1 and 1.75 ng/ml of AFG2, respectively.

0.58 mg of composite A was added to four milliliters of the mycotoxin solution described above to form a solution named solution A. 0.58 mg of composite B was added to four milliliters of the mycotoxin solution described above to form a solution named solution B. Also, 0.44 g of composite C was added to four milliliters of the mycotoxin solution described above to form a solution named solution C. Four milliliters of the mycotoxin solution described above (with no composite A, B or C) were used as a control solution (named control).

The mycotoxin concentration in the aqueous solution was measured by MS by taking 100 pl_ aliquots before the addition of composite A, composite B or composite C (0 min) and at 30, 90 and 180 min after the addition of composite A, composite B or composite C, respectively. In the case of the control solution, 100 mI_ aliquots were taken at 0, 30, 90 and 180 min and their toxin concentration was also measured by MS.

Figure 1 shows the evolution of mycotoxins concentration (ng/ml) (A) DON (B) ZEA, (C) FB1 , (D) OTA, (E) AFB1 , (F) AFB2, (G) AFG1 and (H) AFG2, over time for the different aqueous solutions prepared (control, solution A, solution B and solution C). Each value of toxin concentration has been measured in three independent experiments and error bars showing the standard deviation of the experiment results are shown. As Figure 1 shows, the concentration of all mycotoxins is significantly reduced after the addition of Composite A except in the case of DON. On the contrary, only the concentration of FB1 was significantly reduced after the addition of Composite

B. The addition of Composite C also reduced significantly the concentration of all mycotoxins.

Finally, the particulate magnetic composites were magnetically removed (extracted) from each of the aqueous solutions using a Nd-Fe-B magnet.

Recycling test of the particulate magnetic composite materials.

After the detoxification test, the sorbed mycotoxins were partially or completely recovered by washing said particulate magnetic composites as described below.

Composites A, B and C that have been magnetically removed from the previous solution, were separately added to a washing solution that consist of a mixture of acetonitrile/water/acetic acid in a proportion of 79/20/1 v/v/v. Said magnetic composite materials were washed in a vortex mixer for a minute and then sonicated for five minutes by irradiating said samples with ultrasonic waves (50/60 Hz) resulting in agitation using an ultrasonic bath or an ultrasonic probe. Then, said composites A, B and C were magnetically removed (extracted) from each washing solution using a Nd- Fe-B magnet. Finally, the concentration of the mycotoxins in each washing solution was measured by MS. The percentage of the mycotoxins recovered or extracted in each washing solution was calculated considering the initial concentration of toxins in the detoxification test as 100%.

Figure 2 shows the percentage of the mycotoxins recovered or extracted (extraction %) using (A) composite A, (B) composite B and (C) composite C. The percentages for all mycotoxins recovered from Composite A are over 40% for all the mycotoxins except for DON, being over 80% for ZEA and AFB1 ). Each value of toxin percentage has been measured in three independent experiments and error bars showing the standard deviation of the experiment results are shown. The only recovery percentage over 60% for the mycotoxins recovered from Composite B is in the case of FB1. Recovery percentages over 40% were obtained for all the mycotoxins recovered from composite

C.

Example 2: Detoxification tests of cyanotoxins

Composite A as defined above, was tested for its detoxification capabilities in the removal of cyanotoxins.

The cyanotoxins selected for the test were MC-LR, MC-RR and NOD. These cyanotoxins were obtained from National Research Council Canada (Nova Scotia, Canada).

Mass spectrometry (MS) was the analytical technique used to study the cyanotoxin concentration in the aqueous solutions. A Nd-Fe-B magnet was used for the magnetic driving and separation of the particles Aqueous solutions were prepared as a mixture of the selected cyanotoxins with the following concentrations: 50 ng/ml_ of MC-LR, 12.5 ng/mL of MC-RR and 25 ng/mL NOD, respectively.

0.29 mg of composite A was added to 2 milliliters of the cyanotoxins solution described above (named solution A). Two milliliters of the cyanotoxins solution described above, with no composite A, were used as a control solution (named control).

The cyanotoxin concentrations in the aqueous solutions were measured by MS by taking 100 pL aliquots before the addition of Composite A (0 min) and at 30, 90 and 180 min after the addition of Composite A. In the case of the control solution, 100 pL aliquots were taken at 0, 30, 90 and 180 min and its toxins concentration was also measured by MS.

Figure 3 shows the evolution of the (A) MC-LR, (B) MC-RR and (C) NOD cyanotoxin concentration (ng/ml) in the aqueous solutions over time for the control and for solution A, respectively. Each value of toxin concentration has been measured in three independent experiments and error bars showing the standard deviation of the experiment results are shown. It can be observed in Figure 3 that the concentration of all cyanotoxins is significantly reduced over time after the addition of Composite A. Figure 3 also shows that at least 90 min are necessary to reach a stable concentration (see Figure 3 (A) and (B)).

Then, the composite A with sorbed cyanotoxins, was magnetically removed from the aqueous solution A using a Nd-Fe-B magnet.

Recycling test of the particulate magnetic composite materials by recovering the sorbed cyanotoxins.

After the detoxification test, the sorbed cyanotoxins were partially or completely recovered by washing said particulate magnetic composite as described below.

Composite A, which has been magnetically removed from the previous solution, was added to a washing solution that comprises a mixture of methanol/water in a ratio of 80/20 v/v. Said composite A was washed in a vortex mixer for a minute and then sonicated for five minutes by irradiating said samples with ultrasonic waves (50/60 Hz) resulting in agitation using an ultrasonic bath or an ultrasonic probe. Then, said composite A was magnetically extracted from each washing solution using a Nd-Fe-B magnet. Finally, the concentration of the cyanotoxins in the washing solution was measured by MS. The percentage of the cyanotoxins recovered or extracted in each washing solution was calculated considering the initial concentration of toxins in the detoxification test as 100%.

Figure 4 shows the percentage of the cyanotoxins recovered considering the initial amount of cyanotoxins in the detoxification test as 100%. Each value of toxin percentage has been measured in three independent experiments and error bars showing the standard deviation of the experiment results are shown.

As can be observed from Figure 4, the recovery percentages are over 40% for MC-LR and MC-RR, and close to 20% for NOD.

Example 3:

Detoxification tests of hydrophilic phycotoxins Composite A, as defined above, was tested for its detoxification capabilities in the removal of hydrophilic phycotoxins.

The hydrophilic phycotoxins selected for the test were STX, NEO and dc-STX). These toxins were obtained from Laboratorio CIFGA S.A. (Lugo, Spain).

Mass spectrometry (MS) was the analytical technique used to study the phycotoxin concentration in the aqueous solutions. A Nd-Fe-B magnet was used for the magnetic driving and separation of the particles

Aqueous solutions were prepared as a mixture of the selected toxins with the following concentrations: 20 ng/mL of STX, 20 ng/mL of NEO and 20 ng/mL of dc-STX, respectively. Two milliliters of said hydrophilic phycotoxin solution described above, with no composite A, was used as a control solution (named as control).

0.29 mg of composite A was added to 2 milliliters of the hydrophilic phycotoxin solution described above (named solution A). The toxin concentration in the aqueous solution was measured by MS by taking 100 pL aliquots before the addition of composite A (0 min) and at 0, 30, 90 and 180 min after the addition of Composite A. In the case of the control solution (named control) 100 pL aliquots were taken at 0, 30, 90 and 180 min and its toxin concentration was also measured MS.

Figure 5 shows the concentration (ng/ml) of the hydrophilic phycotoxins (A) STX, (B) NEO and (C) dc-STX, in the solution A at 0 min (initial concentration) and after 180 min of the addition of composite A (final concentration) and at 0 min and after 180 min in the control solution, respectively. Each value of toxin concentration has been measured in three independent experiments and error bars showing the standard deviation of the experiment results are shown.

Then, the composite A with sorbed toxins, was magnetically removed from the aqueous solution using a magnet.

Recycling test of the particulate magnetic composite materials by recovering the sorbed hydrophilic phycotoxins. After the detoxification test, the sorbed hydrophilic phycotoxins were partially or completely recovered by washing said Composite A as described below.

Said composite A with sorbed toxins, which has been magnetically removed from the previous solution, was added to a washing solution that consist of an acidified aqueous media comprising 3 mM of HCI. Said composite A was washed in a vortex mixer for a minute and then sonicated for five minutes by irradiating said samples with ultrasonic waves (50/60 Hz) resulting in agitation using an ultrasonic bath or an ultrasonic probe. Then, said composite A was magnetically extracted from each washing solution using a Nd-Fe-B magnet. Finally, the concentration of the phycotoxins in the washing solution was measured by MS. The percentage of the hydrophilic phycotoxins recovered or extracted in each washing solution was calculated considering the initial concentration of toxins in the detoxification test as 100%. Recovery percentages around 15% were obtained in all cases.

Example 4:

Detoxification tests of lipophilic phycotoxins

The composite A as defined above, was tested for its detoxification capabilities in the removal of lipophilic phycotoxins.

The lipophilic phycotoxins selected for the test were azaspiracid-1 (AZA1 ), azaspiracid- 2 (AZA2), azaspiracid-3 (AZA3), dinophysistoxin-1 (DTX1 ), dinophysistoxin-2 (DTX2), okadaic acid (OA), pectenotoxin-2 (PTX2) and 20-methyl spirolide G (SPX20G). These toxins were obtained from Laboratorio CIFGA S.A. (Lugo, Spain).

Mass spectrometry (MS) was the analytical technique used to study the phycotoxins concentration in the aqueous solutions. A Nd-Fe-B magnet was used for the magnetic driving and separation of the particles.

Aqueous solutions of lipophilic phycotoxins were prepared as a mixture of the selected toxins with the following concentrations: 10 ng/mL of AZA1 , 10 ng/mL of AZA2, 10 ng/mL of AZA3, 10 ng/mL of DTX1 , 10 ng/mL of DTX2, 10 ng/mL of OA, 10 ng/mL of PTX2 y 10 ng/mL of SPX20G, respectively. 0.29 mg of composite A was added to 2 milliliters of the lipophilic phycotoxins solution described above (named solution A). Two milliliters of the hydrophilic phycotoxins solution described above, with no composite A, were used as a control solution (named control).

Then, the toxin concentration in the aqueous solution was measured by MS by taking 100 mI_ aliquots before the addition of Composite A (0 min) and at 30, 90 and 180 min after the addition of Composite A. In the case of the control solution 100 mI_ aliquots were taken at 0, 30, 90 and 180 min and their lipophilic phycotoxins concentration was also measured by MS.

Then, the composite A with toxins sorbed, was magnetically removed from the aqueous solution using a Nd-Fe-B magnet.

Recycling test by recovering the sorbed lipophilic phycotoxins.

After the detoxification step, the sorbed lipophilic phycotoxins were recovered by washing the magnetically removed composite A as described below.

Said composite A with sorbed toxins, which has been magnetically removed from the previous solution, was added to a methanol (100% wt) solution. Said composite A was washed in a vortex mixer for a minute and then sonicated for five minutes by irradiating said samples with ultrasonic waves (50/60 Hz) resulting in agitation using an ultrasonic bath or an ultrasonic probe. Then, said composite A was magnetically extracted from each washing solution using a Nd-Fe-B magnet. Finally, the concentration of the phycotoxins in the washing solution was measured by MS. The percentage of the lipophilic phycotoxins recovered or extracted in each washing solution was calculated considering the initial concentration of toxins in the detoxification test as 100%.

Figure 6 shows the percentage of the lipophilic toxins recovered considering the initial amount of each toxin in the detoxification test as 100%. Each value of toxin percentage has been measured in three independent experiments and error bars showing the standard deviation of the experiment results are shown.